Diagnosis and treatment of diseases of the small intestine remain difficult and time consuming, with poor patient tolerance and uncertain outcome. currently 50 to 100 patients with upper gastrointestinal bleeding are admitted to hospitals per 100,000 population per annum. In 5% of these cases, there will be no identifiable source of blood loss, despite exhaustive testing. Improved means for diagnosis and treatment for these patients are required to reduce their 10% mortality rate. Merix proposes to develop and demonstrate a prototype enteroscopic system which will permit rapid, safe, routine examination of the entire small intestine, to locate and identify sites of gastrointestinal bleeding, and to diagnose other types of small bowel pathology. Utilizing a unique insertion procedure we will be able to insert a diagnostic endoscopic probe transorally to the terminal ileum in less than 30 minutes, without patient discomfort. This procedure will allow routine examination of the 14' of small intestine which presently can only be viewed by procedures which are potentially dangerous or very time consuming. The procedure also has the potential for enabling, for the first time therapeutic enteroscopic treatment of this region as well.